Andrea Leadsom, Leader of the House of Commons, resigned, saying she no longer has faith in Mrs May's ability to deliver a workable Brexit deal.

Brexiteers and leadership candidates are rumoured to be planning a final showdown with the PM later today, telling her it's time to step down.

Cabinet ministers are reportedly furious that they weren't told how far she was planning to go on the crucial issue of a second referendum.

They are under pressure from other MPs to confront Mrs May and make it clear that they will quit if she doesn't.

Mrs May begged MPs in the Commons to get behind her, saying it was the duty of all MPs to make decisions, not duck them.

"If parliament passes the bill before the summer recess, the UK will leave the EU by the end of July," she said.

"By any definition, that alone is delivering Brexit - and by leaving with a deal, we can do so much more besides."

Cabinet ministers met this morning in the so-called "Pizza club" to discuss what to do next - and several of them didn't show up to support her in today's Question Time.

Sajid Javid has requested a meeting with Mrs May where he will reportedly tell her to reverse he pledge on offering MPs a second referendum vote.

In the Commons Mrs May said she was being attacked by British MPs who had told her she had not compromised enough, and others saying she'd compromised too much, and joked she was "looking forward" to voting for a fourth time to deliver Brexit.

"At some stage we have to some together and decide how to deliver Brexit and what people asked us to do," she stressed.

She was jeered by Labour MPs as she again outlined her 10-point offer to them.

But senior Conservative Nicky Morgan warned that she should consider pulling the bill as there isn't enough support for it.

She told the Commons: "The consequences of it not being passed are very serious."

DUP's Nigel Dodds said that Britain were still at the mercy of the EU who could keep us in the customs union indefinitely.

When asked what happens if her bill fails, Mrs May said: "If this House chooses not to take this bill forwards then it is facing itself with a choice of whether it wants No Deal or no Brexit."

BORIS BLASTS MAY

Boris Johnson led the charge of Tories slamming Mrs May's new proposal to finally get Britain out of the EU, saying it's not what the British people voted for.

The ex-Foreign Secretary, who reluctantly backed the deal last time around after repeatedly opposing it, said the ideas were directly against Tory manifesto promises and "I will not vote for it."

He said on Twitter last night: "We can and must do better - and deliver what the people voted for."

Fellow Tory leadership rival Dominic Raab joined him too, adding that he "cannot support legislation that would be the vehicle for a second referendum or customs union."

Today ex-minister Theresa Villiers blasted: "This deal is even worse than the last one. It has all the downsides of the original deal but it would also lock us even more firmly into the EU's customs orbit.

"It is a betrayal and I will not vote for it. It would not deliver Brexit."

Tom Tugendhat, a leading Tory centrist, broke cover and called for the PM to quit after previously remaining loyal to her.

He wrote in the Financial Times: "Leadership matters; it has been absent for too long. This can only change with a new Prime Minister who can inject fresh energy into a moribund process and rebuild the trust necessary to deliver a deal."

Mrs May's 10-point offer unveiled on Tuesday included promises to Labour on holding a vote on a second referendum and staying in a customs union, and attempts to woo Brexiteers with firmer guarantees on getting out of the hated Northern Irish backstop.

But it was met with near unanimous rejection from all sides, leaving MPs in no doubt it would be rejected for the fourth time.

The news comes as she faces a fresh coup from backbenchers.

Brexiteer Nigel Evans told The Sun: "She has U-turned on absolutely everything. We cannot put up with this any longer.

British Prime Minister Theresa May leaves the House of Commons after the weekly PMQ's. Picture: Getty Images

"I will be asking my colleagues tomorrow to agree to a rule change so we can hold an immediate confidence vote if Theresa is not prepared to stand down now."

He added: "It's game over and it's about time the PM recognised that."

Last week they decided to give Mrs May more time - allowing her until after she brings back the deal again before she is told to go.

At the moment British MPs can't vote again to oust her until December, but exasperated Tories want to kick her out now and leave Brexit to her successor.

Jacob Rees-Mogg urged her to consider her position, saying: "I hope the Prime Minister will look at the figures, look at the lack of support for her deal and recognise that, in truth, the PM does not command a majority in the House of Commons."

Pedestrians pass a pro-Brexit banner on a lamp post near parliament in London. Picture: AP

Brexiteer Owen Paterson added: "I very much hope for a coup against Theresa May. We need a new Prime Minister and new Cabinet."

Ex-Tory leader Iain Duncan Smith told LBC Radio: "The key breaking point will be the euros on Sunday and that's when I think we will see people step into action".

He added in TheDaily Telegraph: "The upshot is that Mrs May's legacy is now sure to be a poisonous one - a scorched earth of broken Brexit promises and a party battered by the aftermath.

"Not so much a car crash as a multiple pileup on a three-year road to nowhere."